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Abstract
BSE in the UK
Is Cannibalism to Blame?
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Debate is raging over the origin of the British epidemic of bovine spongiform encephalopathy (BSE). On one side, experts argue it was due to changes in rendering practices (the process of recycling offal into animal feed) introduced in the UK in the 1970s. On the other side, experts propose it was due to cannibalism alone. Before the change in rendering practices, meat and bone meal (MBM) derived from the offal of sheep, cattle, pigs, and chickens was fed primarily to dairy cattle as a high-protein nutritional supplement. In the late 1970s, however, the hydrocarbon-solvent extraction method that had been used previously began to be abandoned, leading to the production of MBM with a much higher fat content.
In through the Out Door
Bacterial Exits Become Eukaryotic Entrances
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The world was transformed when an adventurous cyanobacterium capable of trapping and using the energy in sunlight moved inside another cell. Millions of years later, the successors of that bacterium are chloroplasts, and the cells all belong to the plant kingdom. The success of this union is easy to see. Plants make up some 90 percent of the earth's biomass. The genome project has shown that cyanobacteria have 2,500 genes. But today's chloroplasts have only between 100 and 200 genes. All the rest have moved into the main cellular genome. While some of the proteins encoded by these genes are now used in the cytosol, mitochondria, and plasma membranes, 90 percent have to find their way back into the chloroplast.
Andrzej Krauze is an illustrator, poster maker, cartoonist, and painter who illustrates regularly for HMS Beagle, The Guardian, The Sunday Telegraph, Bookseller, and New Statesman.
